Garry's Mod

Garry's Mod

Zombie/NPC Invasion+
Bug: Can't open the menu anymore
So i was adding some new npcs to my game and accidentally added a broken one. I tried opening the menu to remove it, but the menu just wont open. I get this console error aswell:

[Zombie/NPC Invasion+] lua/autorun/zinv_tool.lua:141: attempt to index global 'SPAWN_MENU' (a nil value)
1. DoClick - lua/autorun/zinv_tool.lua:141
2. unknown - lua/vgui/dlabel.lua:237

this is the only addon that randomly spawns enemies around the map which is exactly what i need, help would be appreciated C: